Evaluation of a side branch ostium in coronary bifurcation lesions is challenging in clinical practice and science. Various methods of obtaining data by means of invasive methods are known, like Optical Coherence Tomography—OCT—and Intravascular Ultrasound—IVUS. Such methods require intervention in blood vessels of the human body. Although a skilled cardiologist is able to control such techniques without much risk, there still is a risk connected to such techniques, in particular a risk of damaging walls of blood vessels.
Therefore, the least amount of invasive actions is preferred. This means it is advantageous to be able to obtain data on the ostium—or opening or cross section—of a specific blood vessel by means of data obtained from another blood vessel of which the specific blood vessel is a side branch. In the paper “First Presentation of 3-Dimensional Recontruction and Centerline-Guided Assessment of Coronary Bifurcation by Fusion of X-Ray Angiography and Optical Coherence Tomography” in the JACC Cardiovascular Interventions journal, a method is proposed by fusing data obtained by means of x-ray angiography—XA—and data obtained by means of OCT. With XA data, a centreline of a sidebranch of a coronary vessel is determined. Subsequently, using OCT data obtained in the main branch, the area of the ostium of the side branch is determined in a plane perpendicular to the centreline determined via the XA data.